Filter cigarette having a permeable band wrap



Dec. 9, 1969 A. c. DAVIS v FILTER CIGARETTE HAVING A PERMEABI-JE BAND WRAP Original Filed Feb. 24, 1965 I. I- s a O l' 0 Q l P: W 'N" Li 1 a I l 8 m I i w 9 F/6'.5 H613 FIG. 4 mm ALFRED C. DAVIS ATTORNEY 8 United States Patent 3,482,579 FILTER CIGARETTE HAVING A PERMEABLE BAND WRAP Alfred Charles Davis, Westbury-on-Trym, Bristol, England, assignor to Imperial Tobacco Company (of Great Britain and Ireland) Limited, Bristol, England, a company of England Original application Feb. 24, 1965, Ser. No. 435,004, now Patent No. 3,410,274, dated Nov. 12, 1968. Divided and this application June 7, 1968, Ser. No. 735,426 Claims priority, application Great Britain, Feb. 27, 1964, 8,091/ 64 Int. Cl. A24d 1/04 US. Cl. 131--9 6 Claims ABSTRACT OF THE DISCLOSURE A cigarette having highly permeable thinned areas formed in the surface of an otherwise substantially impermeable band which band covers the joint between the tobacco portion and the stub portion. The thinned areas overlie the said joint so that as smoke is drawn through the stub, air enters the joint through the highly permeable portions.

The application is a division of my previous application Ser. No. 435,004, filed Feb. 24, 1965, now Patent 3,410,274.

This invention relates to cigarettes of the kind comprising a tobacco portion and a stub joined together in abutting relation by a band that encircles at least a p rtion of both the tobacco portion and stub, and is adhesively secured thereto, to provide a composite cigarette. It also relates to cigars or cigarillos manufactured in a similar manner. Such cigarettes, cigars or cigarillos are hereinafter referred to as cigarettes of the kind described.

i In such a composite cigarette a narrow strip of the encircling band coincides with the butt joint between the tobacco portion and the stub. Hereinafter in this specification said narrow strip is referred to as the line corresponding to the butt joint between the tobacco portion and stub.

The stub may be constituted by any of the well known materials, e.g. crimped paper, cellulose acetate, tobacco, or a hollow mouthpiece, or a composite stub comprising say a section of activated charcoal and a section of crimped paper, and the stub or composite stub itself may be secured within a paper, or like, sheath.

It is an object of the present invention to provide a cigarette of the kind described wherein means are provided to permit air to be drawn into the cigarette adjacent the stub. I

The present invention consists in a cigarette of the kind described, wherein the encircling band comprises a band of substantially impermeable material that is rendered highly permeable at an area or areas on, or a continuous area along, the line corresponding to the butt joint between the tobacco portion and stub of the composite cigarette, whereby air may be drawn in through said line, the volume of said air being controlled by the permeability of the band where it is highly permeable in conjunction with the extent of the periphery of the but joint that is disposed behind said area or areas.

' The encircling band may comprise a band of substantially impermeable material that is rendered highly permeable at an area or areas on, or a continuous area along, the line corresponding to the butt joint between the tobacco portion and stub of the composite cigarette by thinning the material of the band at said area or areas whereby air may be drawn through said line. The

face of the band. The band may encircle the whole length of the stub or only a portion thereof. The volume of said air is controlled by the permeability of the band at said area or areas in conjunction with the extent of the periphery of the butt joint that is disposed behind it or them.

It is to be understood that in the present specification the word areas has been used to indicate that the highly permeable areas are not mere pin-holes.

Embodiments of the present invention will now be described with reference to the accompanying drawings, in which:

FIG. 1 shows a cigarette joined to a stub with a narrow encircling band.

FIG. 2 shows a cigarette joined to a stub with a wide encircling band.

In FIGS. 1 and 2 the encircling bands are shown curled back in places to illustrate the construction.

FIGS. 3 to 5 are examples of different patterns of thinned areas that may in some instances be preferred.

The normal method of manufacturing a cigarette as shown is to roll two cigarettes, with an intervening double length stub, in a gummed double length encircling band, and then cut the stub through the encircling band at its mid point thus providing two single composite cigarettes each comprising a cigarette 1, a stub 2 and a wide encircling band 3 as shown in FIGURE 2. The stub may be ensheathed in its own paper sleeve 4, whilst '5 is the butt joint between the cigarettes and stub.

It is generally considered desirable to be able to provide means for drawing in air with the smoke of a cigarette, in order to reduce the tar passing through it and many suggestions have been made concerning perforating a cigarette or stub with this object in view. Hitherto one of the chief difficulties encountered in reducing and controlling tar is to maintain control of the amount of extra air drawn in. In accordance with the present invention the encircling band for joining a stub and cigarette together is constructed in the following manner, so as to maintain control of air intake and tar reduction.

Material is shaved off the surface of substantially impermeable material to thin it at one or more areas along the line that corresponds with the butt joint between the tobacco portion and stub of the composite cigarette, thus rendering it highly permeable at said area or areas.

In this respect it should be explained that a conventional perforating machine can be set so as to shave material off the surface at spaced intervals rather than form complete perforations thus rendering the material more permeable at said positions according to the thickness of material shaved off.

The band comprises a web 3 of substantially impermeable paper, for example the well known imitation cork tipping material, which is shaved to form circular thinned areas 6 e.g. of about 2 mm. diameter spaced at a convenient distance apart so as to provide, say, four thinned areas around the circumference of a cigarette at equal distances. The line on which the thinned areas are made is the line corresponding to the butt joint between the tobacco portion and stub, ie. it is such that in the finished composite cigarette the thinned areas lie with their diameters coincide with the butt joint 5 between the tobacco portion 1 and stub 2.

For convenience in manufacture, a web of, say, cork tipping material is formed with the thinned area as above described before slitting into widths suitable for material may be thinned by shaving material off a surjoining two cigarettes together. For example the web may be wide enough to be subsequently slit into say fifteen double length encircling bands.

It will be appreciated that by this construction the volume of air that is drawn in with each puff of a cigarette through the areas at which the web 3 is thinned, is controlled by the permeability of the highly permeable thinned areas in conjunction with the extent of the periphery of the butt joint 5 that is disposed behind the thinned areas.

In the event that a paper manufacturer cannot provide a paper of a given degree of permeability, he can at any rate provide paper of a substantially constant permeability.

It is then only necessary to test a batch of cigarettes to ascertain the volume of air drawn in per puff, and assuming too much is drawn in, then the line of thinned areas can be offset somewhat from the butt joint to cover a greater length of the said joint and so reduce air intake. If too little is drawn in, then thinned areas larger in diameter may provided.

It has been found convenient to form the thinned areas on the web of substantially impermeable paper with a perforating machine, that is to say a machine in which the paper web is moved between the circular pegs carried in and protruding slightly from a rotating cylindrical arbor, and a high speed cylindrical cutting head that acts to shave off material from the web coincident with the pegs.

In an alternative arrangement for varying the control of air intake, pegs shaped to produce thinned areas as illustrated in FIGS. 3 to 5, which for convenience can be referred to as lozenge shaped, may be used.

Thus, referring to FIG. 3, which shows a web of substantially impermeable paper 3, the thinned areas 6 are made by pegs which are 3 mm. diameter ground on both sides to provide two parallel flats 8 and 9, 2 mm. apart.

If the thinned areas are then arranged around the cigarette parallel as shown in FIG. 3, then four times 2 mm. of the length of the periphery of the butt joint is exposed through the highly permeable areas of the paper. This shape of thinned area allows for the case when the thinned areas become slightly offset from the jointif circular they will shorten the length of periphery exposed, but if lozenge shaped as shown, a slight offsetting does not alter the length exposed.

While a greater length of the periphery of the joint behind the highly permeable paper can be provided by providing larger thinned areas, e.g. 3 mm. diameter, if four lozenge shaped pegs are turned through an angle of 37, thinned areas as shown in FIG. 4 Will result, where- 'by the length of the periphery of the butt point exposed through the highly permeable areas of the paper is increased by for the four thinned areas, increasing the air intake by a like amount.

If the pegs are turned through an angle of from 60 to 90, thinned areas as shown in FIG. 5 will result. In this case the length of periphery for each thinned area is 3 mm., resulting in an increase of for four thinned areas.

Naturally any shape, number, combination or angular relation of thinned area may be used, but the use of a lozenge shape as shown conveniently permits controlled variation of extent of the length of periphery formed with thinned areas in the paper, without unduly weakening the joining band.

As previously mentioned, in practice the joining band is made double the width of those shown in FIGS. 3 to 5 and is formed with thinned areas close to both edges. The mid-lines of the gaps between the sets of four thinned areas illustrated are the positions at which the web is cut to join two cigarettes and an intermediate double length stub and the double length web is subsequently cut mid-way of its width to provide two composite cigarettes.

The only difference between FIG. 1 and FIG. 2 is that in the former the encircling band does not extend to the end of the stub.

Normally when joining two cigarettes with an intervening stub by an encircling band, the majority of the inside surface of the band is gummed by leading it across a gumming roller Whose periphery is ground down 4- to provide a shallow reservoir containing the gum. The word majority above is used because the reservoir does not usually extend right to the month end 10 (see FIGS. 1, 3 and 4) of the band to avoid gum on the band where the knife severs the double length stub to provide two cigarettes.

When using an encircling band as above described, it is desirable in the gumming operation, i.e. to secure the band to the tobacco portion and stub, to avoid applying gum to the inner surface of the impermeable web at positions too near the thinned areas so that permeability at these thinned areas is unaffected by the adhesive. Chain lines 16 and 116 and dotted lines 11, 12, 13, 14 and 15 have been superimposed on FIG. 3 to assist in indicating the extent of the gumless areas found suitable. The chain lines 16 and 116 indicate where the individual encircling bands 3 are severed. The narrow strip between line 10 and dotted line 11 is a gumless area. The other gumless area is bounded by the lines 12, 13, 14 and 15. The area between lines 13 and 16, but extended across the width of the encircling band, illustrates the extent of the overlap of the ends of the encircling band when the composite cigarette has been completed.

It should be explained that the periphery of the gumming roller corresponds to a multiple of the area between the lines 16 and 116 and of double width, symmetrical about the line 10. The periphery is patterned by machining it to provide a shallow reservoir for gum except at the areas bounded by lines 10 and 11, 12, 13, 14 and 15.

To improve the security of the adhesion of the tobacco portion and the stub to the encircling band, additional gummed areas 17, 18 and 19 may be provided as illustrated in FIG. 4.

It will be appreciated that although four thinned areas are shown in the FIGS. 1 to 5, the number and shape may be varied to suit any particular requirement.

If the substantially impermeable material is pregummed, material may be shaved from the gummed surface or the surface that becomes the outer surface, while if a non pre-gummed material is used, it is desirable to avoid applying adhesive to the inner surface at positions too near the shaved portions. This of course is avoided in the manner described, i.e. by using a patterned gumming roller.

Instead of shaving the line that corresponds to the butt joint between the tobacco portion and stub of the composite cigarette at one or more areas, the line may be thinned continuously by shaving a surface to provide an area, all around the butt joint, that is thinned and is thus highly permeable.

Although a preferred embodiment of the invention has been described in considerable detail, it should be apparent that the invention is capable of variations and modifications by one skilled in the art within the scope of the invention as defined in the claims.

I claim:

1. A cigarette comprising a wrapped charge of tobacco and a filter stub, the stub having first and second ends open to permit the passage of air and smoke and having an outer surface between the said ends, an end of the said wrapped charge of tobacco abutting an end of the said stub to form a joint so that smoke may be drawn through the tobacco and then through the stub, a band secured to both the wrapped charge of tobacco and the said outer surface of the stub and extending across the said joint so as to completely cover the joint and so as to cover a measurable portion of the wrapped charge of tobacco and the said outer surface of the stub to connect together the wrapped charge of tobacco and the stub, said bandbeing substantially impermeable to air except that the part of the band covering the joint has at least one area which is permeable to air, thereby permitting a controlled and limited passage of air through the permeable area into the joint between the wrapped charge of tobacco and the stub, the said area being of a size which is larger than a conventional pinhole, the amount of air which enters at the joint being determined by the amount of the circumference of the joint covered by the said permeable area and the degree of permeability of the said permeable area, said permeable area being constituted by one or more portions which are thinner than the remainder of said substantially impermeable band and said cigarette being radially imperforate between the joint and the end of the stub remote from the wrapped charge, except for the said permeable area.

2. A cigarette as claimed in claim 1 wherein said thinned portion comprises a shallow recess in the otherwise substantially impermeable band.

3. A composite cigarette comprising a wrapped charge of tobacco and an abutting stub portion attached together by an encircling band which is provided with at least one area larger than a conventional pin hole and of greater porosity than the remainder of the band, whereby secondary air may be drawn into the cigarette through said area, characterized in that said area extends cross the plane of abutment between said wrapped charge of tobacco and stub portions and said area is constituted by one or more portions which are thinner than the remainder of the band and said cigarette is radially imperforate between the said plane of abutment and the end of the stub remote from the Wrapped charge of tobacco except for the said area of greater porosity.

4. A method for producing a cigarette of the type having a wrapped charge of tobacco and a filter stub abutting at a joint and attached together by an encircling band, comprising the steps of:

(a) forming in a band of substantially impermeable material at least one thinned area highly permeable to air by shaving off a portion of the surface of the band and (b) attaching the band to the cigarette to join together the stub and the wrapped charge of tobacco, such that the said thinned area overlies the said joint.

5. A cigarette according to claim 1 wherein said permeable area comprises a plurality of separatethinner portions spaced apart around the periphery of said joint of the cigarette.

6. A cigarette according to claim 1 wherein said permeable area consists of a single continuous thinner portion extending around the periphery of said joint of the cigarette.

References Cited UNITED STATES PATENTS 3,279,475 10/1966 Brenner et al. 1319 X 2,693,193 11/1954 Pelletier.

FOREIGN PATENTS 758,429 10/ 1956 Great Britain. 938,902 10/ 1963 Great Britain.

MELVIN D. REIN, Primary Examiner U.S. Cl. X.R. 131-15 

